A Novel Hybrid Plasmonic Waveguide for Nano-Scale Light Confinement and Long Propagation Range

A triangularly configured metal-dielectric-metal hybrid plasmonic waveguide is proposed, with an analysis of its photonic characteristics at 1550 nm, focusing on propagation length and modal confinement. The goal is to achieve a balance between extended propagation and deep-subwavelength light confinement. The structure incorporates Silver (Ag) as the plasmonic metal, Aluminum Gallium Arsenide (AlGaAs) as the high-refractive-index medium, and Polytetrafluoroethylene (PTFE) as the low-refractive-index region. The electromagnetic field is primarily confined within the AlGaAs and PTFE layers, enhancing performance over conventional waveguides. Performance is evaluated using the Finite Element Method (FEM), with variations in waveguide dimensions, angle, and layer thickness. Results have been established that the propagation length of a fundamental hybrid mode of the presented waveguide Lp ∼ 359.01μm with the normalized effective mode area ∼0.0246 at w = 200 nm, h<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AlGaAs</inf> = 300 nm, h<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> = 10 nm and h<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> = 100 nm. This waveguide shows potential for advanced nanophotonic applications, including optical power splitters, photonic couplers, and biosensors.